(4×b - 16) ÷ 2 = 10
4b - 16 = 10×2
4b - 16 = 20
4b=20 +16
4b=36
b=36÷4
b=9
проверим:
(4*9 -16)÷2 =10
(36-16)÷2=10
20÷2 = 10
10=10
(2+х÷7)× 8 =72
2+х÷7 = 72÷8
2+х÷7 = 9
х÷7 = 9-2
х÷7 = 7
х=7*7
х=49
(2+49÷7)×8=72
(2+7)×8=72
9×8 = 72
72=72
35÷(15 -у÷8) = 5
15 - у÷8 = 35÷5
15 - у÷ 8 = 7
у÷8 = 15 -7
у÷ 8 = 8
у=8*8
у=64
35÷ (15 - 64÷8) = 5
35÷(15-8) = 5
35÷ 7 = 5
5=5
(t× 3 + 5)÷ 4 = 8
3t + 5 = 8×4
3t + 5 = 32
3t = 32-5
3t = 27
t=27÷3
t=9
(9×3 +5)÷ 4 = 8
(27+5)÷ 4 = 8
32÷4 = 8
8=8